When a bolt “pushes hard,” the power exerted to push it not being in the line of the axis of the bolt, but upon the end of a handle projecting at right angles from the bolt, it causes the bolt to bind still tighter upon the guard, and is necessarily exerted to a great disadvantage, and usually, in such cases, the bolt "goes up" with a jerk, at the risk of breaking some part of the bolt, and injury to the hand. These difficulties are obviated by the simple device shown in Figs. 1 and 2, of making the slots in the guard of the bolt oblique to its axis, by which the handle becomes a lever for pushing the bolt, with a safe and easy motion to the hand. Letters Patent were granted for this improvement, July 21, 1857. It will be seen that the locking and the leverage are attained without the addition of a single piece, or fraction of expense, over the common bolt. The cost of material and manufacture is the same for both. In Fig. 1, A is the guard of the bolt, E, in which moves the loose handle, 15. This handle plays freely in a hole through the bolt, and is checked in its motions by the shoulder at C, and the swell, D, on the lower end. The bolt is represented as locked, and to unlock it the handle is raised up until the swell on the end is within a countersink in the bolt, and the handle is then used as a lever to move the bolt through the oblique slots. Patents have been taken out for these bolts in England, France and Belgium. License may be had to manufacture these bolts, or the patents purchased, on application to Professor Charles G. Page, Washington, D. C, opposite the city Post-olHce.